18 HIE STORY-BOOK OF SCIENCE 



}n\li'<, two tubes from which, if you look attentively, 

 you can see a little drop ot Mi.n'ary liquid escape from 

 time to time. These black lice are called plant-lice. 

 They are the ants' cows. The two tubes are the ud- 

 ders, and the liquor 

 which drips from 

 their extremity is the 

 milk. In the midst 



J f ^1 V of the herd, on the 



\\ v II r\ , _ 



ssgU herd, even, when the 



cattle are too close to- 

 Piant-iouse gether, the famished 



ants come and go from one louse to another, watching 

 for the delicious little drop. The one who sees it 

 runs, drink, enjoys it, and seems to say on rais- 

 ing its little head: Oh, how good, oh, how good it 

 is! Then it goes on its way looking for another 

 mouthful of milk. But plant-lice are stingy with 

 their milk; they are not always disposed to let it run 

 through their tubes. Then the ant, like a milkmaid 

 ready to milk her cow, lavishes the- most endearing 

 caresses on the plant-louse. With its antennae, that 

 is to say, with its little delicate flexible horns, it gen- 

 tly pats the stomach and tickles the milk-tubes. The 

 ant nearly always succeeds. What cannot gentle- 

 ness accomplish ! The plant-louse lets itself be con- 

 quered; a drop appears which is immediately licked 

 up. Oh, how good, how good ! As the little paunch 

 is not full, the ant goes to other plant-lice trying the 

 same caresses. 



Uncle Paul let go the branch, which sprang back 

 into its natural position. Milkmaids, cattle, and 



